1. Field of the Invention
The present invention relates to a solid insulated switchgear, and more particularly, to an interlock apparatus for an solid-insulated switchgear.
2. Description of the Conventional Art
Solid-insulated switchgear is a switchgear in which insulation among the phases of the three-phases alternating current by an insulating gas such as a sulfur hexafluoride (SF6) gas is substituted by a solid electrically insulating material such as epoxy, which is used as a material in a portion except for the portion requiring electrical conduction of the constituent element, in a sulfur hexafluoride (SF6) gas-insulated switchgear in the related art as one of green house gases the use of which is globally trending toward restrictions. Such a switchgear is typically used in the reception and distribution of electric power lines, branching of a line, and the like.
The present invention relates to an interlocking apparatus, i.e., interlock apparatus, for preventing a main circuit switching mechanism and a ground circuit switching mechanism from being simultaneously closed, in other words, preventing both of the two switching mechanisms from being simultaneously closed in such a manner that the ground circuit switching mechanism is not at the ground position when the main circuit switching mechanism is at the conducting closing position, in a solid-insulated switchgear having a structure in which the main circuit switching mechanism and ground circuit switching mechanism are connected in parallel among the solid-insulated switchgears.
As an example of the interlock apparatus according to the related art, there is Korean Utility Model Registration No. 20-0183457 (Title of the utility model: Mechanical interlock apparatus in air circuit breaker) filed and registered by the applicant of the present invention
However, the above introduced interlock apparatus according to the related art has a vertical structure, thus providing an unsuitable structure in applying to a solid-insulated switchgear to which the present invention with a parallel structure is to be applied in which a main circuit switching mechanism and a ground circuit switching mechanism are provided in a horizontal direction. In the aspect of structure, it has a structure to be operated while the link is pulled by a wire, thereby causing a problem that the wire is likely to be cut off by repetitive use of it, the maintenance work is inconvenient due to its complicated structure, and the miniaturized size is not attainable in applying it to a solid-insulated switchgear in which the dimension of the occupied three-dimensional space is limited.